Dermatitis herpetiformis(DH) is a blistering skin disease characterized by the presence of cutaneous IgA deposits and an associated gluten sensitive enteropathy(GSE). The critical role of the mucosal immune response(MIR) in DH has been demonstrated by the observation that despite the lack of clinical symptoms of GSE in the majority of DH patients, the cutaneous manifestations of DH can be controlled by a gluten free diet. The mechanisms that allow for the development of cutaneous IgA deposits and skin disease yet that prevent the development of symptoms of GSE are not known. The purpose of this project is to characterize the MIR in patients with DH in order to determine the factors which prevent the development of clinical signs of gastrointestinal disease yet result in cutaneous deposits of IgA and the development of the cutaneous manifestations of DH.